While sitting or standing in a natural position, a patient's teeth should have an orientation that appears well centered and leveled in reference to the patient's facial features. Horizontal and vertical reference planes must be considered to create an attractive and natural looking set of teeth that allow for proper mastication and occlusion. If a patient's face were perfectly symmetrical, the mid-line between the central incisors should be parallel and centered with the sagittal mid-line. Additionally, the patient's maxillary anterior incisal line, also known as the “bite plane” or “bite register”, should be parallel with the inter-pupillary eye line, a horizontal reference plane, and perpendicular with the sagittal mid-plane. However, very few individuals have perfect facial symmetry and dental orientation.
Often, bite impressions of the teeth necessary for dental restorations, prosthodontics, orthodontics or other procedures are taken without information regarding the orientation of the teeth or bite plane relative to the features of the face and head. Without the proper orientation, the resulting dental casts can lead to the creation of dental restorations with improper occlusion of the patient's teeth and numerous aesthetic problems including an unnatural bite plane or a slanted maxillary mid-line and gum line.
As patients became increasingly concerned with proper function, appearance and aesthetics of their dental work, methods were developed to provide an accurate orientation of the bite plane. For example U.S. Pat. No. 2,695,451 is directed to a device for determining the proper alignment of upper and lower jaw impressions, U.S. Pat. No. 2,908,975 is directed to a device for orienting impressions taken for making dental plates, bridges and other dental work, U.S. Pat. No. 3,200,497 is directed to a method of reproducing the spatial orientation of bite impressions for the production of dental replacements and dentures, U.S. Pat. No. 4,639,220 is directed to an apparatus for measuring the three-dimensional position of upper and lower bite impressions for fabrication of dental prosthesis, U.S. Pat. No. 5,810,586 is directed to an apparatus to determine the placement and relative position of upper and lower dentures, U.S. Pat. No. 6,109,917 is directed to a dental apparatus for determining a patient specific reference plane for aesthetic positioning of dental casts, and, finally, U.S. Pat. No. 6,413,085 is directed to a system for configuring and aligning anterior maxillary teeth. The disclosure of each of these references in incorporated in its entirety herein. None of these devices allow a rapid determination of the patient's bite plane with a rigid apparatus that is easily adjustable for determining the horizontal and vertical planes of a patient's face, and, can be locked to record a correct position of the determination.
It would be desirable to provide an apparatus and method for easily and accurately determining the bite plane of a patient in relation to the horizontal and vertical symmetry of the patient's face and head. Such apparatus and methods for determining bite plane orientation of a patient that easily accommodates variance in patient symmetry and anatomy would be further desirable.